Pneumatic tool holder



III

L. C. COLE PNEUMATIC TOOL HOLDER Filed Aug. 20. 1921 Nov. 27, 1923.

Patented Nov. 27, 1923.

vUnirse .srarss ariane Parser orsi-cs.

LYNDON C. COLE,v OF HAMILTON, OHIO, ASSIGNOR TO` NILESeBEMENT-PONDCOMPANY,

OF NEW YORIL'N. Y., A CORPORATION OF NEW JERSEY.

PNEUMATICI 'TOOL HOLDER.

I yApplication led August 20, 1921. Serial No. 493,986.

l To all vwhom t may concern:

Be it4 known'thatl, LYNDoN. C. COLE, a

Vcitizen of the United States-residing at Hamilton, in the county ofButler and tate of Ohio, have invented certa-in new and usefullmprovements .in Pneumatic Tool Holders, of which the following is aspecification.

rlhis invention relates to. tool holders for lathes and other machinetoolsand partic- V ularly tov a tool holderadapted to be operated bypneumatic means.

An object of the present invention is .to provide an improved toolholder adapted to be .operated by pneumatic.v means toi clamp and tounclampa tool between the cooperating jaws of the holder.

. Av further object of the invention is to provide a construction whichwill prevent the tool from .becoming unclamped when the air pressure isaccidentally released from the pneumatic cylinder. A still furtherobject of the invention is to provide pneumatic means-for positivelyunclamping the tool from the tool holder.

One feature which enables me to accomplishthe above mentioned `objectsis .the provision of a double acting cylinder .adapted tovr haveeitheriof its ends connected with a source .of fluid under pressure, theaction of t-he fluid within the cylinder Vserving to lower or raiseaxpiston therein.

Another feature which is advantageous is `that theupward movement of thepiston, whichserves to clamp the tool'between the jaws of the holder,operates a bellA crank lever, a short arm of which is carried by thisclampingmovement slightly beyond a position. normal Ato thel jaws to a.self-locking positionso that, shouldthe pressure within the cylinderbev released, vunclamping of 'the Vtool will not occur.

With these and otherobjects .in view, my invention consists in thefeatures `of construction andv operation set forth in thefollowingspecification and illustrated in the accompanying drawings.

In the accompanying drawing annexed hereto and forming a part ofthisspeciication,l haveishown invention embodied in a tool holderadapted to be mounted on the cross-slide of a lathe, but it will beunderstood that the invention can be otherwise embodied and that thedrawing is not to be construed as defining or limiting the scope ofVthis` :inventiomthe claims appended to this yspecification being reliedupon for that purpose. i

In the drawing:

Figure 1 isan elevation in section of the complete tool holder.

tions may be made with-in the scope of the appended claims withoutdeparting from the spirit of the invention.

Briefly, `my invention in its broadest aspect comprises thefollowingprincipal parts:

rst,a tool supportadapted to be mounted on the crossslide of a lathe;second, a movtable jaw member cooperating with the tool Asupport to holdatool in position, third,

means, preferably adjustable, for connecting the tool supportand movablejaw member together; fourth, a bell crank lever for tilting the upper awabou-t its adjustable connection to clamp an'd unclamp a tool; lifth, adouble acting piston wiithin a suitable cylinder for operating said.bell cranklever.

i vReferring, more in detail to the figures of the drawing, thestructure consists of a tool support 10 having-adovetail opening 11 onits lower side adapted tolit a. corresponding tongue on the cross-slideof a lathe or other ,machinetool At one side of this tool support isahardened steelI plate 12 forming one of the jaws of the tool holder. iSecured in. the tool supportfis a bolt 15A preferably threaded into thetool support 10 and hav- ,ing a nut 16 engaging threads 17 at its outerend.v

Surrounding the bolt is an upper movable jaw member 20 having at oneside. hardened plates 21 forming a pair of bearing surfaces for `thetool holder.

These plates 21, as seen in the ligures, are directly over the hardenedplate 12inthe tool support 10. Between the .tool support I10 and themovable jaw member plates l2 and 2l may be varied within wide limits toadapt the tool holder for different sizes of tools such shown at A.

Secured to the upper surface of the movable jaw member 2O is a cylinder24 adapted 'packing rings 29 and 30 on its upper and lower faces.Connected to the piston 28 is a piston rod 32 extending through thelower end surface of the cylinder 24 through a suitable stuffing box 33.The lower end of the piston rod 32 is connected to a short connectingrod 34, the opposite end of which is pivotally connected to a bell cranklever 35.

rllhis -lever 35, which forms the operating member for clamping` andunclamping the jaw 20 of the tool holder, is pivotally mounted about ashort shaft 38 resting in bearings provided in the tool support 10.rlhis lever 35, preferably, is in the form as shown in Fig. 3'whichcomprises a bell crank lever having arms of unequal length.

The longer arm 35a is, as above stated, piv" otally connected to theconnecting rodk 32. rlhe other arm 35b of this lever is very short andextends approximately at right angles from the longer arm. A bearingplate 40, which may be suitably hardened. is inserted in the lowersurface of the movable jaw member 20 in the position engaged by theshorter arm 35b of the bell crank lever d5.

To hold the free end of the movable aw member in its lowermost positionI secure a bolt 42 in the tool support l0 extending' freely through themovable jaw member 2O and having` a nut 43 at its outer free end.

Jietween the nut 43 and the upper surface of the movable jaw member 2O lmount a helical spring 44. rlhe effect, therefore, of this spring 44 inconnection with the spring 23 surroundingthe boltJ 15 is to hold thejaws 12 and 2l of the tool holder at a maximum distance apart when thebell crank lever 35 is in its unclamping` position.

To operate this tool holder it is only necessary to open a valveconnecting 4the lower end of the cylinder 24 with fluid pressure whichcauses the piston 23 to move upward. rlhis oscillates the bell cranklever 35 about the center of the short shaft 38 and moves the shorterarm 35b of the bell crank lever 35 into the position shown in dottedlines in Figs. l and 3. Preferably the movement of the piston 32 issucient to move this short arm 35b of the bell crank lever 35 slightlybeyond a vertical plane passing` through the. axis of theshaft 3S sothat it is securely locked in position and a failure of pressure withinthe lower part of the cylinder 24 will not permit the bell crank lever35 to move to its opposite or unclamping position. To unclamp the toolholder it is only necessary to admit fluid pressure to the upper end ofthe cylinder 24 which will force piston 28 downward and oscillate thebell crank lever 35 to the position shown in full lines. By the actionof the springs 23 and 44, the jaws l2 and 21 are then moved to theiropen or unclamping` position.

lNhat l claim is:

l. A tool holder comprising` in combination, a tool support forming thelower fixed jaw of a tool clamp, an upper movable jaw cooperating'therewith. means to flexibly connect said movable jaw to the tool support, a bell-crank 'lever between the tool support and the movable jaw,and pneumatic means to oscillate saidbell-crank lever to its extremeposition to clamp a tool mounted within said holder, said bell-crankbeing so formed that when moved to clamping position the movable jaw isheld in a self-locking position.

2. A tool holder comprising in combination, a tool support forming thelower fixed jaw of a tool clamp, an upper movable jaw cooperating'therewith, means to flexibly connect said movable jaw to the toolsupport, a bell-crank lever between the tool supportand the movable jaw,pneumatic means to move said bell-crank lever to its position to clamp atool mounted `within said holder and to lock said bell-crank lever inclamping` position, and pneumatic means to unlock said bell-crank leverand move it to unclamping' position to release the tool from saidholder.

3. A tool holder comprising in combination, a tool support forming thelower fixed kjaw of a tool clamp, an upper movable jaw cooperatingtherewith, means to flexibly connect said movable jaw member to the toolsupport, a bell-crank lever between the tool support and the movable jawmember, pneumatic means to move said bell-crank lever to its position toclamp a tool mounted within said holder, said bell-crank lever beingmoved to a selfelocking position, pneumatic means to unclamp saidholder, and resilient means forcing said adjustable jaw toward itsunclamped position.

In testimony whereof, l hereto afiix my signature.

LYNDON C. COLE.

